1. Field of the Invention
Embodiments of the invention generally relate to the field of semiconductor manufacturing processes and devices, more particularly, to methods of depositing silicon-containing films for forming semiconductor devices.
2. Description of the Related Art
As smaller devices are manufactured, ultra shallow source/drain junctions are becoming more challenging to produce. Generally, sub-100 nm CMOS (complementary metal-oxide semiconductor) devices require a junction depth to be less than 30 nanometers. However, ultra shallow source/drain junctions inevitably result in increased series resistance. One approach for reducing series resistance includes heavily doping the epitaxial films used in forming the device. However, heavily doped films can degrade film quality due to dopant surface poisoning and increased film roughness. Additionally, high dopant levels achieved during cyclical deposition processes may result surface segregation during etching and purge steps.
Therefore, there is a need for forming high quality epitaxial films having reduced resistivity.